Aromatic color couplers containing mercaptan and hydroxyl groups



Patented May 13, 1 952 AROMATIC COLOR COUPLERS CONTAINING MERCAPTAN AND HYDROXYL GROUPS g.

Richard V. Young and Arnold Weissberger, Rochester, N. Y., assignors to Eastman Kod'akCoiii- A pany, Rochester, N. 1 a corporation of New Jersey No Drawing; Application January 13,1948, Serial No. 2,127v

5 Claims. 1

This invention relates to color-forming or coupling compounds and particularly to coupler compounds capable of forming-insoluble silver or other metallic salts. v

Peterso'nU; S. Patents. 2;296,30.6and 2,353,724 describe photographic color couplers containing a heterocyolic system having a free imino or cercapto group capable'of forming an insoluble metalliosalt when thecompound is incorporated in a photographic emulsion. These compounds are non-difius'ing'in the photographic emulsion, but-byreason' of a coupling group combinewith the development: product of' primary aromatic amino agentsto form colored. images in the wellknown'manner; On fixing, the metallic atom attached to the imino or mercapto group is removed. andthe, unused coupler can theoretically be washed from the layer. The couplers described in the Peterson patents are undesirable for certain'reasons, mainly. because theyare relatively complex and cannot be easily removed from. theemulsion layer in the unexposed portions. This produces-residual stain and printouts."

It is therefore an object of the present invention to provide a new class of coupler compounds from which insoluble metallic salts may be formed in the emulsion layer. A further object is to provide couplercompounds which are readily soluble; in the fixing bath and which may be readily removed from the'emulsionlayer. Other objects will. appear from the following description of our invention.

These objects are accomplished by incorpo-' rating in the emulsion layer: a coupler compound containing at least twoaromatic rings, one of which has a mercapto group attached thereto and another of which'has attached thereto. a group rendering the compound capablexofcoup1ing:with-the oxidation-product of the develop.- ing. agent. The dyes formed inithis. way are of the well-known dyes: of;the quinoneimine: (Cain and'Thorpe; Synthetic, Dyestuffs, 1934, page, 265 and-azomethine (British Journal ofPhotography, vol. 85, 1938, page 628) classes. The following: compounds illustrate our invention.

2'-hydroxy-4-mercaptodiphenyl l-hydroxy-ES-mercapto-naphthalene l-hydroxy-firmercapto-naphtlialene do 020111, 1 1-mercapto'5-carbethoxynaphtl1ol (5 O CH2C N 1-mercapt0-5-cyanoacetyl naphthalene 1-mercapto-fi hydroxyanthracene- 01- NH0 0- I 3. Q C E: SE

4,6-dich1oro5-methyl-2- (3 -mercaptobenzoylamino phenol 0-0 001120 ONH-C SH' p Benzoylacetanii-nothiophenol 9 O-ooome ONH SOzNHO-SH 4- (p-benzoylacetamino benzene sulfamidothiophenol 4' (p-benzoylacetamino)benzene aminobenzoyll-thiophen01 CaH5C OGHEC ONE. 7 SO NH 2- [p- (w-benzoylacetamino)'+benzenesulfonamido] r4 chloro' thiophenol CNCHzCO SOzNH- 2- (2-cyanoacetyl-x-naphthalenesulfonamido) -4-chlorothiophenol The coupler compounds used according to our invention are generally incorporated in the emzilsion layer by first forming a solution of the sodium or other soluble salt of the corpler and then incorporating this solution in a relatively light insensitive silver halide emulsion, whereupon part of the silver of the silver halide replaces the sodium to form the silver salt of the coupler. Other heavy metal salt dispersions such as gold, nicirel, mercury, cadmium or tin may be formed before the coupler is incorporated in the light sensitive silver halide emulsion. Silver salts are preferred, however, since a silver salt is ordinarily used in the preparation of sensitive layers and common silver salts such as silver chloride or silver bromide are suitable for thepurpose of our invention. Other silver salts which may be used to make the silver salt dispersions include silver ferricyanate, silver ortho-phosphate, silver arsenate, silver oxalate, silver cyanate and silver citrate. Y

The non-diffusing metal salts made according to our invention may be incorporated in single or multi-layer'gelatin emulsion coatings or in layers of other colloidal materials such as cellulose esters or natural or synthetic resins and mixtures of the couplers may be used in a single layer.

The couplers of our invention may be prepared as follows:

Compound 1;--2'-hydromy-4-mercapto-diphenyl O OH 1 OOSEOCQHE KOH l HCI Compound 4.1-mercapto-5-cctr bethorynaphthol 1-carbethoXy-naphthol-fi-sulfonyl chloride is reduced with zinc dust and hydrochloric acid to bis-1-carbethoxy-naphthol-5-disulfide. The disulfide is then reduced to l-mercapto-S-carbethoxy naphthol with aluminum and hydrochloric acid.' The product is extracted with benzene, distilled and crystallized from ligroin to give a ksosocgm compound having a melting point of 44 C. The reaction may be indicated as follows:

Compound 7.-4,6-dichZoro-5-methyZ-2 (3- mercaptob'enzcylamino) phenol give a compound having a melting'point of 176- Compound 8.-p-Benzoylacetaminothiogohenol 'This compound is prepared by adding freshly prepared p-amino thiophenol to a hot solution of 10% excess benzoyl acetic ester in xylene, the alcohol being eliminated during the condensation by distillation. The product melting at 139-140". C. is crystallized from benzene.

Compound 9.4-(p-benzoylacetamino) benzene sulfamidothz'ophcnol Compound 11., 2-lp-(w-benzoylaeetamino) benzene sulfonamidol -4-chlorozhiophenol This compound is prepared. by treating p-(w-benzoylacetamino) benzenesulfonylchloride,

Which is obtained in the manner described in Porter and Weissberger 2,350,127, with 2-amino- 4-chlor0thiophenol in the presence of sodium acetate and acetic acid at 50 C. The product which melts at 195 C. is crystallized from petroleum ether-ethyl acetate. The reaction may be indicated as follows:

NaOAc H OAc 50 C.

' sitive layers from blue light.

Compound 12.-2- (2 cyanoacetyl X naphthalenesulfonamz'do) -4-chlorothiophenol This compound is prepared; by treating 2-cyano acetyl X naphthalenesulfonylchloride,

which is prepared" as described in Porter and Weissberger 2,350,127 with 2-amino-4-chlorothiophenol hydrochloride in the presence of sodium acetate and acetic acid at 50 C.- The. product which melts at90 C. is crystallized from dilute acetic acid. The' reaction may be indicated as follows? CNCHlCO HOAc 50 C.

SH oNomo o SOzNH-Q The following examples which are illustrative only indicate a method of forming a multi-layer photographic element using the couplers of our invention.

A solution of coupler capable of producing a cyan dye is prepared by dissolving 4.0 grams of 2'-hydroxy-4-mercapto-diphenyl in 80 cc. of a 2% sodium hydroxide solution. A fine-grain silver chloride emulsion is prepared in the usual manner containing 4.3 grams of silver chloride in 900 cc. of a 2.0% gelatin solution. The solution of the sodium salt of the coupler is added with rapid stirring to this fine-grain silver chloride emulsion. This forms a silver salt of the coupler in very fine dispersion. The coupler dispersion may then be mixed with an equal volume of a higher speed sensitized emulsion and coated on a support spreading 40 grams of coupler per thousand square feet of surface.

A solution of a coupler capable of producing magenta dyes is prepared by dissolving 4.5 grams of 1-mercapto-5-cyanoacetylnaphthalene in 80 cc. of a 2% sodium hydroxide solution. A finegrain silver chloride emulsion is prepared in the usual way containing 4.3 grams of silver chloride in 900 cc. of a 2% gelatin solution. The solution of sodium salt of the coupler is added with rapid stirring to this fine-grain silver chloride emulsion. This forms a silver salt of the coupler in very fine dispersion. The coupler dispersion may then be mixed with /2 the volume of a higher speed grain sensitized emulsion and coated on the red sensitized layer spreading 45 grams of coupler per thousand square feet of surface.

A yellow filter layer is coated over the green sensitive layer to protect the red and green sen- This filter layer may consist of a very fine dispersion of silver prepared by the Carey Lea Dextrin Method. It should be coated so that it has a density of 2.0 to light of 420 millimicrons wave length.

A solution of a coupler capable of producing a yellow dye is prepared by dissolving 5.4 grams of p-benzoylacetaminothiophenol in 80 cc. of a 2% sodium hydroxide solution. A fine grain silver chloride emulsion is prepared in a well-known manner containing 4.3 grams of silver chloride in 900 cc. of 2% gelatin solution. The solution of sodium salt of the coupler is added with rapid stirring to this fine-grain silver chloride emulsion; This forms a silver salt of thedouplerliin very'fine dispersion. The coupler dispersion may then be mixed with the volume of a higher. speedunsensitized emulsion and coated overv the filter layer. The layer of yellow'coupler'isthe top and'final coat of the multi-layer coating. and should be spread to contain about 90. grams-of coupler per thousand square feet of surface.

The emulsion layers coated in this way produce respectively cyan}. magenta and yellow images upon development-with a rimar amino are mati'c developing ag'ent such as dietnyi-p-pnenyl amine diaminex The" sensitive element may beexposed and developed directly t'o' fo'rm a negative' colored image or a positive image by first developing' in an ordinary bla'ck-and-white developer followed by color development of the residual silver halide.

The emulsions containing our coupler compounds are developed with any suitable primary aromatic amino developing agent such as the solution described in Peterson 2,296,306 and 2,353,754. Development is preferably carried out for about five minutes at 65 F. after which the element is treated with a weak acid stop bath such as acetic acid, followed by ferricyanid and hypo bath to remove the silver and any undeveloped silver halide which the film contains. These baths may also remove any unused coupler.

Our couplers are easily removed from the emulsion layer in the undeveloped portions, and for this reason the residual stain and print-out are reduced. Furthermore, our couplers can be recrystallized, and therefore can be prepared in a pure state.

It will be apparent that the emulsion layers made with the couplers of our invention may be coated on any suitable support such as cellulose nitrate, cellulose acetate, glass or synthetic resins or on opaque supports such as paper or pigmented esters.

The modifications and examples included herein are illustrative only and it will be understood that our invention is to be taken as limited only by the scope of the appended claims.

We claim:

1. The method of producing a colored image in a silver halide emulsion layer, which comprises exposing said layer and developing it with a primary aromatic amino developing agent in the presence of a coupler compound comprising a naphthalenic compound containing a hydroxyl group in the 1-position of the naphthalene ring rendering'the compound capable of coupling with the development product of said developing agent, and having a mercapto group attached to another aromatic ring of said naphthalenic ring.

2. The method of producing a colored image in a silver halide emulsion layer, which comprises exposing said layer and developing it with a primary aromatic amino developing agent in the presence of a coupler compound comprising a 1- hydroxy-mercaptonaphthalene having the mercapto group attached to the other aromatic ring of said naphthalene.

3. A light-sensitive gelatino silver halide emulsion containing a coupling compound having at least two aromatic rings, one of which has a mercapto group attached thereto and another of which has attached thereto-a hydroxyl group, rendering said compound capable of coupling with the development product of a primary aromatic amino developing agent to form a dye selected from the class consisting of quinoneimine and azomethine dyes.

4. A light-sensitive gelatino silver halide emui+= sion containing a coupling compound having a .hydroxyl group in the l position of a naphthalene.

ring; said hydroxyl group rendering the compound capable of coupling with the development prodact of a. primary aromatic amino developing agent and said-compound also having a mercapto group attached to the other aromatic ring of said naphthalene. lr .1. 5. 'A light-sensitive :gelatino silver halide emulsion layer containingv a l-hydroxy-mercapto naphthalene coupler compound having the mercapto group attached to the other aromatic ring of said naphthalene. Y

a RICHARD V. YOUNG. V

ARNOLD WEISSBERGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,401,718 Young June 4, 1946 2,448,939 Weissberger et a1. Sept. 7, 1948 FOREIGN PATENTS j Number Country Date 836,144 France Oct. 10, 1938 

3. A LIGHT-SENSITIVE GELATINO SILVER HALIDE EMULSION CONTAINING A COUPLING COMPOUND HAVING AT LEAST TWO AROMATIC RINGS, ONE OF WHICH HAS A MERCAPTO GROUP ATTACHED THERETO AND ANOTHER OF WHICH HAS ATTACHED THERETO A HYDROXYL GROUP, RENDERING SAID COMPOUND CAPABLE OF COUPLING WITH THE DEVELOPMENT PRODUCT OF A PRIMARY AROMATIC AMINO DEVELOPING AGENT TO FORM A DYE SELECTED FROM THE CLASS CONSISTING OF QUINONEIMINE AND AZOMETHINE DYES. 